Shenandoah 1965

From Amazon:
Shenandoah, a film well-liked in its day, recalls Friendly Persuasion and foreshadows The Patriot as it tells of an American clan traumatized by war on native soil. Virginia farmer James Stewart has never owned slaves, owes allegiance to no one beyond his own kin, and adamantly disregards the North-South strife rumbling just over the hill: "This war is not mine and I take no note of it." That changes when youngest son Philip Alford (To Kill a Mockingbird's Jem) is carried off by Yankees, and the family must ride out to reclaim him. Shenandoah has several affecting moments--notably a homefront...

Long before Mel Gibson did The Patriot, James Stewart did a similar movie set in the War Between the States. Only Stewart didn't access his inner warrior and go off to avenge his sons; he realized and accepted the tragedy for what it was - senseless and stupid.